Many people carry cellular telephones, beepers, and other personal electronic devices (“PEDs”). When incoming telephone calls or pages are received at these devices, an audible alert is sounded (e.g., a ringing or beeping noise emanates) to inform the owner of the incoming message. These audible alerts can be disturbing to nearby persons, and, in some venues, inappropriate. For example, it is inappropriate for someone to have a ringing telephone during a performance in a concert hall. One solution to this burgeoning problem is to give notice to persons entering designated areas that such devices are to be turned off; however, with the proliferation in number of cellular telephones and pagers that are being brought into any given space, there is an increasing need to free individual users of the responsibility of turning off their electronic devices or of setting such devices to a quiet alert mode (e.g., vibrator mode). The present invention satisfies that need by automatically squelching the ringing or beeping noises of any such device while it is within a designated space, regardless of the alert mode setting of a particular device.